TM 9-2320-260-34-1
5-25. FUEL PUMP CALIBRATION (Contd)
f. Testing and Adjusting Throttle Leakage
1. Increase fuel pump(5) speed to 2100 rpm. Place selector valve (8) in rotameter position and set fuel
flOW control valve (1) at 315 pph reading. Rotameter float should read 315 pph on test stand (2).
2. Place selector va]ve (8) in leakage test position. Place count selector switch (7) to 1000 pulse
position. Pull out dumping lever (3) to retain fuel in number one burrette (4).
CAUTION
Do not hold throttle lever in idle position for more than two
minutes to complete test. Damage to fuel pump may occur.
3. Remove throttle spring (9) and position throttle lever (10) in idle position.
4. Depress pulse counter button (6) to fill number one burrette (4).
5. To prevent fuel overflow, push dumping lever (3) inward to empty number one burrette (4) of fuel.
NOTE
A test cycle is one-half minute duration.
For one test cycle fuel delivery is 40-70 cc.
6. At end of cycle, read amount of fuel in number one burrette (4).
NOTE
Adjust throttle screw counterclockwise to decrease leakage.
Must throttle screw clockwise to increase leakage.
7. If throttle leakage is not as specified, adjust rear throttle screw (11) as necessary.
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